'Eggshells can be a conduit': Perth researchers crack renewable energy alternative
Advertisement

'Eggshells can be a conduit': Perth researchers crack renewable energy alternative

It's an egg-cellent time for renewable energy, according to Murdoch University researchers.

Eggshells have raw chemicals that can be naturally replenished and used for power.

Eggshells have raw chemicals that can be naturally replenished and used for power. Credit:Jessica Shapiro

The Perth scientists have discovered how baked eggshells crushed into fine powder can work as a cheap alternative to store renewable energy.

Deputy head for research Dr Manickam Minakshi has carried out a series of tests on supermarket bought-caged eggs since November 2017 to figure out if eggshell powder can work as positive and negative electrodes to power batteries.

"Eggshells have a high level of calcium carbonate, which can act as a form of replenishing energy,” he said.

Advertisement

"What’s interesting is that the egg membrane around the yolk (a protective barrier) allowed us to cook it at a high temperature, crush it into powder and bake it at 500 degrees Celsius with the chemical still present.

Dr Manickam Minakshi and PhD student Kethaki Wickramaarachchi ground the cracked egg before baking it to incite a chemical reaction.

Dr Manickam Minakshi and PhD student Kethaki Wickramaarachchi ground the cracked egg before baking it to incite a chemical reaction. Credit:Murdoch University

"The final baking process changes the chemical composition from calcium carbonate to calcium oxide and allows it to become a conduit for electricity."

For Dr Minakshi’s team, the find is a first step towards work on an alternative battery to store energy from renewable energies such as solar panels and wind turbines.

"Renewable energy resources are intermittent as they depend on the weather," he said. "When we have an excess, we need a battery to store it. Ground egg shells serve as the electrode to store this."

Electrodes require opposing reactions to create a conduit. Before being heated, the eggshell is a positive electrode, but when it starts heating it changes to be a negative electrode and a reaction sparks.

Dr Minakshi said he hoped the project was picked up by renewable energy companies as using abundant and affordable materials like eggshells had the potential to address bio-waste if testing proved successful on a larger scale.

"You can buy them at a 12-pack from Coles for $4 or pick them up from the food court," he said.

"What’s even more important is that you can use the eggshells that are thrown into landfills. This brings in the potential to reduce the amount of bio-waste we produce."

Dr Minakshi said the team would next test the longevity of the eggshell’s conduit abilities, studying how long the battery cells last before they need to recharge.

They will also test to see if free-range eggshells have better conductive qualities.

Advertisement